Firefox won't remember two log-ins for my banking site... how do I fix this?

Mozilla used to allow me to remember two different log-ins with different passwords on my banking site (two different accounts). Now (in the last 2 months) when I ask Firefox to remember one of the log-ins, it will not permit me to enter the other log-in with password....it keeps overriding with the other account's log-in and password. How can I have Firefox remember both (like it used to do)??